Retired biologist outmuscled menacing mollusks

Zebra mussels became infamous in states bordering the Great Lakes about 25 years ago. Many newspaper and magazine articles have been published about the invidious and menacing mollusks since they scurried into public awareness.

I’ve never seen a zebra mussel up close, but I’ve read many of those articles and studied the photos of clusters of the pests. Without fail, each of those stories included this observation:

“The zebra mussel has no natural predator.”

That meant there were no amphibians, fish, birds or other creatures that would be pursuing and eating the mussels. That could be filed under the heading of bad news; it gave worriers something else to fret about. It was especially bad news for managers of municipal water treatment and sewage plants, as well as power plants and other industrial users of water.

The mussels affix their little selves—they are about the size of a jellybean—to water intakes and other piping networks, clogging the systems, reducing efficiency, hampering production and being more than a major headache. They are a certified nuisance.

They usually get most of their public scrutiny during boating season. They reproduce at an astronomical pace. By the millions, they cling to the anchors and hulls of boats and many docks in over 30 states. While there is an impact on boating, most of the anxiety relates to clogged pipes, primarily plant water intakes. Clusters of mussels can become so dense they reduce the flow to a trickle.

Efforts have been made to control the mussels using copper, chlorine and other chemicals. The results have been mixed. The use of chemicals has been opposed by many groups that warn against the impact on fish and other wildlife and the pollution of lakes and rivers.

Finally there is some good zebra mussel news, however. There is a predator—not a natural predator but a human one named Daniel P. Molloy, a retired biologist from the New York State Museum in Albany, now on the faculty at SUNY Albany. He is well-known for the development of environmentally safe agents to replace chemical pesticides.

Before embarking on his mollusk extermination mission, Molloy achieved a measure of fame as the leader of a scientific group that found a method to decimate the black flies that annually plagued the Adirondack area. It was a quest that took him to various frontiers. He discovered an unusual bacterium in a pond in Israel and, after much testing, it proved to be deadly to the larvae of black flies. The flies were a monstrous seasonal problem, hovering ominously around tourists and inflicting painful bites. Controlling them made summer in the Adirondacks more pleasant.

In 1990, he began his quest for a solution to the zebra mussel infestation, which was spreading to a larger part of the country each year. He speculated about the possibility of finding bacteria that would do to zebra mussels what the bacteria from Israel had done to black flies.

It was no easy task. It took 20 years, during which he and his team tested more than 700 bacterial strains. One discovered in river mud was found to be lethal to the mussels while having no adverse effects on the environment. After approval, a California company began distribution of the products with great success.

Now there is a new challenge for Molloy. Those succulent oysters found in Chesapeake Bay and along the Atlantic Coast have been under attack by a parasite, and he is assembling a team to find a solution.

“If we work hard enough and long enough and are lucky enough, we can find the answer,” Molloy observed.